One of the problems that fitness professionals deal with is answering extremely broad questions, the most common of which is “What should I eat?” Now, if I want to be a smart ass, the only way to answer an unfairly broad question is with an unfairly broad answer, so I just say, “Food.”

When I’m not being a smart ass, I ask the client to hone in on the question a little bit more. In order to tell you what or how much you should eat, you need to figure out the goal: fat loss or muscle gain?That brings us to problem number two: most people want both.

More to the point, most people don’t want to deal with the ramifications of selecting one over the other. If they go on a traditional “bulking” diet for gaining muscle, they’ll put on fat. That’s not fun for anyone. Conversely, if they try to diet down to get lean, they run the risk of losing hard-earned muscle.In either instance, it’s a losing proposition.

Which brings us to problem number three: Most people want to lose fat while gaining muscle, but experience has shown them that it’s impossible — because they’ve been going about it all wrong.You see, body recomposition (the term we use for simultaneous fat loss and muscle gain) isn’t impossible; it’s just tricky. The reason most people screw it up is because they approach the goal primarily through training, which isn’t the best way. Attempting to train for muscle gain a few days a week and then do cardio for fat loss a few days per week won’t work — unless you adjust your diet for that.

The truth is, it is possible to achieve recomposition, but it’s mostly a matter of diet.

But how?

In order to allow for muscle gain, you need to eat above your energy needs. On the opposite side of that coin, losing fat requires that you eat less than your caloric needs.

So, how do we reconcile these things when they seem to be diametrically opposed?

It’s simple: We look at caloric needs in terms of individual days, rather than as a more universal measurement.

Put another way, on some days you take in more calories, and in some less — all determined by your activity level. That activity, of course, is weight training.

To use fitness parlance, we’re talking about something called cycling. In this case, we’re talking about carb cycling and calorie cycling, which means that on days you train with weights, you take in more calories and carbs, and on “off” days, you take in less. “Off” days are days where you do cardio (but no weights) or don’t train at all.

Of course, in order to make use of that, you first have to know how to determine your calorie needs, for both training and non-training days.

And when it comes to determining caloric needs, we look at calorie formulas.

First, we need to establish one very important fact: all calorie formulas — no matter who gives them to you, or how great they look on paper — are ultimately a crapshoot. That is, certainly such formulas will be generally applicable, but anyone who tries to tell you they know exactly how many calories you need to eat at any time, ever, is either lying or simply doesn’t realize how ridiculous they are. Of course, some formulas are better than others, but even the best ones should mainly serve as a jumping off point from which you can make changes.

Got it?

Great.

Now that we’ve established that, let’s go further and acknowledge that calorie formulas come in all shapes and sizes. And, like anything else, some are better than others.

The most basic formulas simply ask you to take your weight and multiply it by an integer between 12 and 16. According to these formulas, that gives you the amount of calories you should be eating. Subtract a few for weight loss, add a few for muscle. The problem with such a calculation is that it allows for no differentiation between fat and muscle.

The obvious problem there is that someone who weights 200 pounds at 10% body fat will have vastly different energy needs than someone who weighs 200 pounds at 30% body fat. The first person has 180 pounds of lean body mass (LBM) and 20 pounds of fat, whereas the second has 140 pounds of LBM and 60 pounds of fat. In order to reach their respective goals, they’ll need to eat differently.

So, it’s pretty obvious that simple formulas like that aren’t really very beneficial in the long run.

More advanced formulas base calculations on lean body mass, rather than just on weight. Figure out the clients’ LBM, and multiply it by a number, usually 16.

This is a lot better, obviously. Using the example from above, the calorie needs of those 200-pound clients would be different, perhaps vastly.

It’s better, but it’s not perfect. And that’s because such formulas are only using one part of a person’s body composition to determine their energy needs: their lean body mass. But not their fat.

This is a huge oversight. People of similar LBM might have very different calorie needs, based on their levels of leanness.

For example, a 200-pound client at 10% body fat has 180 pounds of lean mass. Now let’s look at a 275-pound client with 35% body fat. He’s got 178.75 pounds of lean mass.